Looper driving mechanism



4 Sheets-Sheet 1 A. H. wEls LOOPER DRIVING MECHANISM Filed Nov. 1929 EZGQI ZH 7/2123 May 2, 1933. A, was 1,906,294 I LOOPER DRIVING MECHANISM Filed Nov. 5, 1929 4 Sheets-Sheet 3 May 2, 1933. A. H. WEIS 1,906,294

LOOPER DRIVING MECHANISM Filed Nov. 5, 1929 4 Sheets-Sheet 4 85 ,rin jg 6P 29 P8 60' :I 5 6, 9 w

Patented May 2, 1933 UNITED: snares:

PATENT o' Fic-Ei:

ALBERT H..-..WEIS,?F-1\TYAGK,,.NEW YoaK, Assisnoa roiivrnraoiotrriiiv snwmG...

MACHINE coaronarrcn, or. :mmcx, new roan, .a oeaeeaiir on .011 DELAWARE LOOP-ER DRIVING MECHANISM...

Application filed November 5,

This invention relates to sewing machines; and more particularly to. a .loopen driving mechanism;theneforea the object of theain: vention being to provide. an improved looper driving mechanism for singlevand .multiple needlemachines which :is simple in .con: struction-,-durable in operation, comparativeinexpensive to l manufacture and sulostantially'ifree from vibration whenaoperating at high speeds, .andwvhich .is effective to I give the' -looper a short-throw or movementdn:

propertimed relation with a needle harhaving: a high lift, whereby; the'stitching 1necha-:

nisni: is particularly adapted forsewing thick; worln and in which ltheseveralelements are so constructed and organized that; they will operateatv high speed witha .aninimum of vibration.

A further :object of the invention. is the provisionaof. an improved :lOopezwdriving mechanism by. [means 0f. :which. a variable movement will: be;--imparted1-.to;the; looperwherebyzit will-ha veadwell, thereby ena: blingit to co-operatezlwitha needle. having .a *high lift.

Another'ob'j-ect ofitheinvention is the pro. vision of an improved. looper driving mechas: nism efiectivetohgive xtherloopen-a short throw.wranovement .in proper. timed melee: tion :n'ith .a needle having a high llfil,\Vl1lCl1"i looper driving-mechanism will enable the needleto be. set- :higher to give added needle; clearance above the; work without the. necessity: of increasing the .throw of the; needle bar,;-:.whereby the machine is jcapable .of[ higher speed, will standup better, and there w is less-wear. and tear onthe. parts and loss vibration.

Heretoiore in sewing machines it has been the. practice tOuPI'OVldG. a looperv driving mechanismforia imparting. to the, .looper a long thrower :movement; substantially corresponding to thei-movementiior {lift- ;of. the needle. Inother words, i the loopers usually hai es a movement back and .forth', eqnalj to r. the2.-up and .!down everti-cal reciprocation. of: the LI19Clle, SO that, for instance, when the; needlehas. an .ineh and .a half. ,vertical 'move' ment,-:the: loopeii also hasaninch and" a half:

50 back and forthiimovement to -ins'urepthe.

1929. SerialNo: L915.

proper-:timing of it-hefpartsfor-"accurate stitching and high speed. As there is :only about %a quarter of 'a'n' inchaclearance-zbetween the point of the needle and theatop surface r of the throat-plate, there are numerous disadvantages in a long-throw looperroneaof which is the difliculty T Of sewingv thick-'gwork, dueto the slight clearance between the point:; of the needle: and the top surfacefotther throat-plate; It was not practical'toalengtheefiti en the connection orvpitrnan' between the needle "bar and the; driving vcranlt therefor, thereby; to increasethis needle clearance,- as this would necessitate theirraising ot the top shaft and toparniand not only. make.

unsightly machine, but" would result .in-.: other Weaknesses by reason =ofthe long-icon nectin-g rods 'transinittingmpower from.-1therbottom shaft tot-ha top shaft,-Eincreasingthee.

vibration, wear and tear speed of thepmachine': By ymeans of: the present;-improvement; however, whereby a variable motion is'giv enn to the looper so that it; will have thesiprop'er dwell, it is necessary'to give the-looper.only-7 about five-sixteenths; or three-eighths of zan inch 'inevelnen-t and, therefore,-:considerahly less movement than the needlevand yet have, the proper timed relation with respect to tl e needle and-:alsoSenable the needle ,toibepsetzs 1 and reducing, the:.70i

higher by about three-eighths'rof an iinchw with :thesame) illlfOWuOf the needle. =bar. :iand-: thus get. an added Zneedle clearance saber e the iclotheplat-e, while: permitting the parts i to operate at-higher; speed with? less vibrae;

tion and less wear and tear 011 'tl1e:;parts; Henceathe present. improvementrshas many:

im'poitant advantages over: machinesin which the looperdriving mechanism imparts to the looperithe same lengthiof movement as;;that= of the: needles -among which advane tages iszthe elimination of costlyizmachineiv elements heretofore used for impa'rtingjthe.v throw to thelooper suchsas spiral gears."

The presentnim-provement'is shown 21,11 plied to, the; well-known 'longearin Metro-r politan sewing-.inacliine. having top and 1 bottomgrotary shaft."

In'the drawings accompanying. and. forms inga part of. this Tspecifica-tion+- I i Figure 1 is a front view of a sewing machine with this improved looper mechanism applied thereto, the framework of the machine being illustrated in dotted lines and in section;

Fig. 2 is a left-hand, partly sectional, end view of Fig.1; i P

Fig. 3 is a top plan view of the mechanism located below the cloth-plate of the machine, with the trunk of the machine in section so as to clearly show the looper operating mechanism.

Fig. 4 is a front view of Fig. 3, showing the looper in its foremost position;

Fig. 5 is a detail plan view, partly in section, of the looper slide and its operating means; I

Fig. 6 is a perspective view of the feed bar and needle guard;

Fig. 7 is a perspective view of the looper operating mechanism; 7

Fig. 8 is a top plan view ofthis improved looper operating mechanism for operating a tandem pairof loopers for making four parallel rows of stitches simultaneously; and

Fig. 9 is a front view of Fig. 8.

Similar characters of reference indicate corresponding partsin the several views.

Before explaining in detail the present improvement and mode of operation thereof, I desire to have it understood that the invention is not limited to the details of construction and arrangement of parts which are illustrated in the accompanying drawings, since the invention is capable of other embodiments, and that the phraseology which I employ is for the purpose of description and not of limitation.

The base or base-plate 1 of the sewing machine carries a hollow trunk 2 having a overhanging arm 3 terminating in a head 4. A belt-wheel 5 is carried by a crank-shaft 6 mounted in bearings 7 and 8 of the base 1, and this crank-shaftis connected by three connecting rods 9 with a crank-shaft 1O sup-" ported in bearings 11 and 12 of the overhanging arm. To the rear end of this crankshaft 10 ahand-wheel 13 is secured, and to the front end of this shaft a needle bar drivco-operates with a throat-plate 19 and the usual feed dog 20 for feeding the work; This feed dog is carried by a feed bar 21 (see Fig. 6) pivotally connected by a short shaft 22' (see Fig. 2) to the top of the feed rocker frame 23, the bottom of'which is pivotally connected, as at 24, to the machine base; The feed bar 21 is provided with a strap 25 (see Figs. '2 and 6') co-operating with the feed lifting eccentric 26 for giving the up and down movement to the feed dog,

crank-shaft 6 by a coupling 31. This coupling so connects the crank-shaft 6 and main shaft 30 that they operate as one shaft and thus this coupling facilitates the manufacture, assemblage and adjustment of the parts. The back and forth movement of feed dog is obtained by means of-a connection 27 (see Fig. 3), one end of which is connected, as at 28, to the short shaft 22 while the opposite end is operated by an adjustable crank 29 carried on the front end of the mainshaft 30.

The trunk 2 carries an extending portion or apron 32, to which is attached one end of a cloth-plate 33, the opposite end of which is supported by a standard or bracket 34 of the base 1 and also by a support or arm 35 attached to the base 1, as at 36 (see Fig. 1). This support .34 for the cloth-plate also forms a bearing 37 for the front end of the main or bottom shaft 30, and the feed lift eccentric 26 is carried by this main shaf close to this bearing (see Fig. 5). A har-. dened steel washer 38 acts as a flange for the eccentric and also a face against which the two halves of a split block 39 operate. This split block forms a bearing for an eccentric 40, which has a collar or flange 41 for securing it to the shaft 30, the split block thus being located in the spacebetween the washer 38 and the collar or flange 41' of the eccentric, so that its movement back and forth is controlledby these parts. The two halves of this split block 39 are located between an upstanding jaw 42, formed as a part of a dovetail slide 43, and an adjustable jaw 44 secured to the dovetail slide by screws 45,so that as the shaft 30 and its eccentric 40 are rotated, a reciprocating motion is given to the slide 43 crosswise of the machine bed and at right angles to the main drive shaft30, this 'slidebeing held in place.

on the base of the machine (see Fig. 4) by a. pair of gibs 47 co-operating with apair of beveled edges 46 of the slide. This re-.

ciprocating slide 43 is provided with a pair of lugs'48 and 49 tapped "to receive a pair of conical screws 50 and which are locked in place by any suitable means and form a support for the looper rocker bearing 51 (see Fig. 7). This looper rocker extends upwardly and is provided with'a socket in the top portion 52 thereof for the reception of a thread-carrying looper 53-lield in place by a screw and nut 53' (see Fig. 4) which also holds a thread eyelet 54in place for leading the 'threadto the looper; A ball stud 55 is tapped into the looper rocker, and this ball stud is received in a ball socket 56 secured to a connecting rod 57 the opposite end of which is also provided witha ball socket; r58 .openating .on .a ball. studv59: carriedlbyan arm-=60 of what may be designate, ed as a two-arm:leversecured bya screw-69 x to a short. vertical shaft or-stud .61. which )ivotallyoperates in vertical bearings 62: and 63 carriedby a supporting bracket 6 L. secured to the machine base-r1 by screws 65. (see Figs; 2,3 and 4); The other arm.66

. position; indicatedv by .B '.(Fig.:; 3):'.which:&

corresponds tothe distance betweensthentwo" .w

ofthe two-arm lever 60 is-also provided with "an adjustable iball stud 67-s-ewred to the arm 66; by a screw68 for in :and out adjust ment-relatively-to the arm 66. This. ball stud67 is carriediby a ball socket -70'con-' nected-to one endof a rod 71,]the opposite 1 end 'of which is connected. to'an: eccentric strap72 co-operating withaball eccentric 73 see Fig.3) provided with aflange or collar 7% secured to the-.main shaft 30. By

meansof this eccentric 73 mounted on the 1-: main shaft 30 and the connecting mechanism j ust. described, the looper is reciprocatedlinto and out of the needle loop, while the eccentric 40 also mounted on the mam shaft 30 reciprocates the slide43 to carry the looper from. front to rear of the needle at each stitch cycle of the machine for the forma' tion-of the stitches As the looper moves forward into the needle loop, the front side thereof gently contacts with the needle, and

=as it moves backward while the needle is descending to enter a loop of looper thread,

the n edle gently contacts with the back of the looper, the needle and looperthus forming the stitches.

The organization just described thus per mits the formation of stitches with a very short looper movement. Heretofore it has been the practice to have a looper movement approximately equal to the vertical movement of the needle, so as to insure the proper timing of the looper in its cooperative action with the needle and thus permit the looper to enter and leave the needle-loops fast enough to permit the drawing up of th'e' 1 stitches without undue tension, as well as to stitch accurately without frequent missing of the needle loop;- The present improved loopermechanism, however, permits a short looper movementor a shortthrow looper with a high needle "lift especially adapted for sewing over thick work, whilepermit ting high speed of the'parts." This short looper movement has many advantages over the long looper movements By means of the looper driving mechanism herein describedferencein the length of movement of -the looper heretofore deemed necessary. This variable; motion is Lobtained. by the p'eouliara organization ;of, theaparts y-whe'rleby; the l0cai-; 7 tion of. the averticaloshaft-fil relative' to the;

main driving shaft: 30' and thelooper'carrierr 52is such asitocause-the .connection 57 to 1.

swing fIOlIhtllG: position shownin fulllines; 1 in Fig. to .the dotted-line 0sitionAf2(Fig. f 3)., thereby bringing therbalistud 59 to thee ward movement of the;looper-. V r Thus when the; arm 60' of-;the

a dwell occurs in themovementof the looper loopera carrying lball stud 59 is caused itolswing out-.

ward past the center. ofltheverticalrshafti 61,-

which :takes place atethe time the -looper isle shifted to the left while theneedle. loop is.) on .the -.looper. A change; in the length of...

the connection 171, by adjusting this. connec-ation,. will effect .the relative position a of movement of the arm 60 so that. va'ri-ations..=

within certain limits of theivariablemotion of thelooper for speedanddwell can beobtained, and this adjustment also effects. a change in the-distance of travel alongsthev line C-D representing 5 the. lengthwise,

movement of the looper.

A short. movementof thealoopers in IHUltlL-I.

ple needle machines is of. considerable im-.

portance in order. to obtain certain ,-needlei.

gauges for making closerows of= stitches.

Loopers operating at right'angles to thelineti" of feedhave certain advantages and loopers operating in line with the feed have advazn: tages because'it is possible to arrange needle guards and also to obtain higher needles movement or clearance above the cloth-platen 7 for bulky work. 7 V

In the presentimprovement, therefore, it

'will be observed that by'giving a variable:-

motion and dwell to the looper-I am able to give the looper-a short 'looper fmovement without effecting its timed relation with a needle having a high lift: which will permit theparts to operate-'athighspeed; This short loopermovement permits the setting of the needle higher, byabout three-eighths 1 of an inch, With the: same throw 'to-the V needle bar, thus giving greater clearance 7 between the point of the needle and-the top surface of the throat plate for the stitching of bulky Work thus eliminating the necessity ofincreasing the throw of the needle bar'by j a longer pitman connection, known that long-throw needle move} ment 1s detrimental to high speed and, there fore," any increase in the throwof-the needle bar by increasing the length of the pigaan connection will be a serious disadvantage for It is well I the weight of the bar-,the length of its move-' j merit, andthe angleof'therlriving pitman all set up such a side thrust when the pit'mair is directly opposite the horizontalcenter line of the top shaft as to cause excessive wearvery much the same proposition that the engineers of automobile engines have been up against all along with the short connecting rods and long piston movement. The connecting pitman between the needle bar and its operating crank, as hereinbefore stated, cannot well be lengthened because that would necessitate the raising of the top to-be handled, while with certain kinds of work the thread control may be entirely dispensed with.

From the foregoing it will be observed that in the present improvement, by means of thevariable motion given to the looper, it need only have about five-sixteenths or three-eighths of an inch movement back and forth without affecting its timed relation with respect to the needle having a high lift or length of movement, and yet notwithstanding this short movementthe needle can be set hi -her thereb increasin the clearance between the needle point and the workplate without increasing the length of the pitman connection of the needle bar. This short looper movement, therefore, is capable of higher speed, stands up better, and there isless wear and tear on the parts and less vibration.

In Patent No. 1,264,585, dated April 30,

1918, of the Metropolitan Sewing Macl'iine Corporation (the assignee of the present improvement), is shown a looper driving mechanism in which the looper-s have a long throw corresponding to the lift or movement of the needle. In this patent the loop er is operated back and forth by means of a shaft extending crosswise 1n the base of the machine, which shaft is driven by spiral gears, so that the looper has a rotary drive by means of a ball connecting rod reaching from the gear-driven crank-shaft to the looper. These spiral gears are expensive to make. Figs. 8 and 9 of the drawings show 7 how this improved short looper driving mechanism may quickly and conveniently be. substituted for the spiral gear drive shown in the patent referred to. To effectthis substitution it is merely necessary toprovide a holding bracket 76 supported at the reel thereof, as at 77, by adjusting nuts and a bolt carried by the base 1 at the rear of the machine. Thefront end of this bracket is supported by two conical screws 78 tapped into lugs 79 of the base, which is cut out as at 79. Thus that portion 64 of the bracket which forms a bearing for the vertical shaft 61 is supported by a three-point support. The part 64 is in the form of a bifurcated bearing bored to receive the vertical shaft 61 upon which is pivotally mounted, for swinging movement, the two-arm rocker lever, one arm 60 of which carries the ball stud 59 while the other arm66 carries the ball stud 70, this lever being rocked by a connecting rod 71 extending to an eccentric strap 72 co-operating with a ball eccentric 7 3 on the main shaft 30, and this gives a rocking movement to the two-arm lever and, therefore, a variable movement and dwell to thelooper. The "bracket 76 is provided with an opening 80, thus providing space for the eccentric 73 and the strap 72connected with the connecting rod 7l I preerably provide an intermediate bearing 81 "for the main shaft 30 to prevent springing of the shaft at high speed when the looper driving mechanism is driving two or more loopers.

In these Figs. 8 and 9 four loopers are shown set to cooperate with four needles set.

obliquely for making four independent rows of stitches. These loopers are located in the looper carriers 52 carried by the looper support the left-hand looper carrier, the

slide 13 is provided with extending arms 8% carrying the conical screws 50. For the chiferent needle gauges, except for a slight difference in spacing of the looper rockerswhich is provided for by different spacings between the looper rockers and the conical screwsall that is necessary is a change in the length of the link 82. A change from a one-inch gauge to a two-inch gauge, however, would require a similar change in the pivotal supports for the looper carriers or rockers.

A needle guard 85 (see Fig. 6) carried by the feed bar 21 is provided to contact with the needle close to the underside of the looper just prior to the looper entering the needle loop.

The improvementshown in Figs. 8 and 9, whereby thelcopers maybe given a variable movement and dwell, thereby effecting a short looper movement, may readily be substituted on machines now in use having the form of looper mechanism shownin the patent referred to and equipped with a spiral drive, since it is interchangeable there with by any mechanic, who can substitute one for the other in a very short space of time.

This improved looper driving mechanism is capable of higher speeds, is more durable, and requires less repairs, because of the shorter throw of the loopers, than longthrow loopers, while permitting a high-lift needle to have greater clearance space between the point thereof and the cloth-plate for the sewing of bulky work, as well as having many other advantages. a

It is to be understood that by describing in detail herein any particular form, structure or arrangement, it not intended to limit the invention beyond the terms of the several claims or the requirements of the prior art.

Having thus explained the nature of my said invention and described a way of constructing and using the same, although without attempting to set forth all of the forms in which it may be made or all of the modes of its use, I claim:

1. In a sewing machine, the combination with needle mechanism and means for imparting a high lift to the needle, a looper carrier adapted to carry a looper and supported for rocking movement back and forth, means for shifting the looper from front to rear of the needle and transversely of its rocking movement, and means for imparting such rocking movement to the looper and including driving means, a connecting rod and lever mechanism between said driving means, and rod effective simultaneously with the rocking of the looper to shift the rod laterally in the arc of a circle, one end of the connecting rod having a back and forth movement for operating the looper, the opposite end being operated by said lever to swing in an arc, a portion of which are is substantially a right angle to the direction of the other movement, so as to impart a variable motion and dwell to the looper whereby it will have less movement than the high lift movement of the needle.

2. In a sewing machine, the combination with needle mechanism and means for imparting a high lift to the needle, a looper carrier adapted to carry a looper and supported for rocking movement back and forth, means for shifting the iooper from front to rear of the needle and transverseiy of its rocking movement, and means for imparting such rocking movement to the looper and including driving means, a connect ing rod, and lover mechanism between said driving means and rod and comprising a pivotally supported two arm rocking lever movable in a substantially horizotal plane, one end of the connecting rod havijg a back and forth movement for operating the looper, the opposite end being operated by said lever to swing in an arc, a portion of whic i are is substantially at a right angle to the direction of the other movement to impart a variable motion and dwell to the looper whereby: it will have less movement than the high lift movement ofthe needle; I

'3. In a sewingmachine, the, combination with needle mechanism and means for imparting a high lift to the needle, a looper carrier adapted to carry a looper and supported for rocking movement back and forth, eccentric means for shifting the looper from front to rear ofthe needle and transversely of its rocking movement, and u means for imparting such rocking movement to the looper and including eccentricdriw ing means, a connecting rod, and lever mechamsm bet-ween said-driving means and rod effective simultaneously with the rocking of the'looper to shift'the rod laterally in the arc of a circle, one end of the connecting rod having a back and forth movement for operating the looper, the opposite end belng operated by said lever'to swing in an arc, a

portion of which are is substantially at a right angle to the direction of the other movement, thereby to imparta variable motion anddwell to the looper whereby it will have less movement than the ment of the needle. 7

4. In a sewing machine, the combination with needle mechanism and means for imparting a high lift to the needle, a sliding, looper carrier adapted to'carry a looper supmeans and rod and efiective simultaneously with the rocking ofthe looper to shift the rod'laterally in the arc of a circle, one end of the connecting rod having a backand forth movement for operating-the looper, the opposite end being operated by said le ver to swing in an arc, a portionof which arc is substantially at a right angle to the direction of the other 'movement, so asto impart a variable motion and dwell to the looperwvhereby awn have less movement than the high lift movement ofthe needle.

5. In a sewing machine, the combination with needle mechanism and means for imparting ahigh lift to theneedle, a looper carrier adapted to carry a looper and supported for sliding movement in one direction and for rocking movement in a trans-* verse direction, means for sliding the looper, and means for rocking the loopenincluding a connecting rod and lever mechanism, one 7 end of the connecting rod having a back and forth movement for operatingv the looper, the opposite end being operated by said high lift movelever to move in an arc, a portion of which is substantially at a right angleto the direction of the other movement, thereby to impart a variable motion and dwell to the looper.

6. In a sewing machine, the combination with needle mechanism and means for imparting a high lift to the needle, a plurality of linked loopercarriers adapted to carry loopers and supported for sliding movement in one direction and-for rocking movement in a transverse direction, means for sliding the loopers, and means for rocking the loopers, the latter including a connecting rod and lever mechanism, one end of the connecting rod having a back and forth movement for operating the loopers, the opposite end being operated by said lever to move in an are, a port-ion of which is substantially at a right angle to the direction of the other move-- ment, thereby to impart a variable motion and dwell to the loopers. 7

7. In a looper driving mechanism for sewing machines, the combination with needle mechanismand means for imparting a high lift to the needle, a looper carrier adapted to carry a looper and supported for sliding movement in one direction, and for rocking movementin a transverse direction, means for sliding the looper, and means for rocking thelooper, the latter including a connecting rod and lever mechanism, one end of the connecting rod having a back and forth movement for operating the looper, the opposite end being operated by said lever to move in an arc, a portion of which is substantially at a right angle to the direction of the other movement, thereby to impart a variable motion and dwell to the looper, such rocking means including a connecting means located substantially at right angles to its driving means, and connecting means located transversely to said first connecting means and movable at a varying angle to'the driving means.

' 8. In a looper driving mechanism for sewing machines, the combination of a looper carrier adapted to carry a looper and supported for sliding movement in one direction and for rockin movement in a transverse direction, means for sliding the looper, and means for rocking the looper, the latter including a connecting rod and lever mechanism, one end of the connecting rod having a back and forth movement for operating the looper, the opposite end being operated by said lever to move in an arc, a portion of which is substantially at a right angle to the direction of the other movement, thereby to impart a variable motion and dwell to the looper.

Signed at Nyack, county of Rockland and Stateof New York, this 2nd day of November 1929.

. ALBERT H. WEIS. 

